Sen. Bernie Sanders (I-Vt.) in a letter to United States Postal Service on Tuesday demanded answers on how letter carriers are being protected during the coronavirus pandemic, after reports that postal workers haven’t had access to needed sanitation and protective gear.

Sanders, who remains in the race for the Democratic presidential nomination, urged the postmaster general to “protect employees and customers in the wake of an unprecedented public health crisis.”

The senator’s letter cited a report by ProPublica earlier this month, in which some letter carriers said they were pressured to keep delivering mail despite having symptoms of illness. Others said they had little to no access to hand sanitizer on the job.

Sanders also linked to a report in The Nation last week saying carriers reported not being given soap, disinfectant wipes or gloves.

As of Tuesday, over 200 postal workers have tested positive for coronavirus, according to the USPS — more than three times as many as last week. This is still a relatively low figure among a workforce of about 630,000. But as testing is ramping up nationwide and the virus continues to spread, more cases are likely to emerge.

USPS told HuffPost that it would be responding directly to Sanders’ letter and that the “safety of our employees is our highest priority.”

The agency said it was “making gloves and surgical masks available to all employees,” and pointed to its increased coronavirus-related paid leave for workers to use for childcare or if they’ve come into contact with someone with COVID-19, the disease caused by the virus.

As millions of Americans have been ordered to stay home to protect themselves and stem the spread of coronavirus in recent weeks, postal workers nationwide are still going to work, risking their health to deliver the letters, government benefits, prescriptions and more mail that people need and rely on.

The workers are part of a workforce deemed “essential” during the coronavirus crisis, meaning that — like grocery store workers, firefighters, garbage collectors and more — they still have to show up to work every day, even as large swaths of the country have closed stores and schools, and companies have mandated employees work from home.

Last week, HuffPost spoke to a postal worker union leader who said his members didn’t have enough sanitizer to meet their needs. And a letter carrier, discussing the stress he is feeling, told HuffPost that he is on the go all day without access to a bathroom and can’t easily comply with guidelines from the Centers for Disease Control and Prevention telling people to wash their hands frequently. He hadn’t found any hand sanitizer for sale in his town, and his supervisor said the jug they all share at work was the last on hand.

“I just wear rubber gloves and try not to touch my face — I don’t know what else to do,” the carrier said. “I actually think I’m going to get the virus, it’s just a matter of time.”